Questions 23-33
The preservation of embryos and juveniles is a rate occurrence in the fossil record.The tiny, delicate skeletons are usually scattered by scavengers or destroy by before they can be fossilized.Ichthyosaurs had a higher chance of beingpreserved than did terrestrial creaturesbecause,asmarine animals, they tended to live inenvironments less subject to erosion. Still, their fossilization required a suiteof factors: a slow rate of decay of soft tissues, little scavenging by other animals, a lack of swift currents and waves to jumble and carry away small bones, and fairly rapidburial. Given these factors, some areas have become a treasury of well-preserved ichthyosaur fossils.
The deposits at Holzmaden, Germany, present an interesting case for analysis. The ichthyosaur remains are found in black , bituminous marine shales deposited about 190 million years ago. Over the years, thousandsof speciments of marine reptiles, fish, and invertebrates have been recovered from these rocks.
The quality of preservation is outstanding, but what is even more impressive is the number of ichthyosaur fossils containing preserved embryos. Ichthyosaurs with embryos have been reported from 6 different levels of the shale in a small area around Holzmaden, suggesting that a specific site was used by large numbers of ichthyosaurs repeatedly over time.The embryos are quite advanced in their physical development; their paddles, for example, are already well formed. One specimen is even preserved in the birth canal. In addition,the shale contains the remains of many newborns that are between 20and 30 inches long.
Why are there so many pregnant females and young at Holzmaden when they are sorare elsewhere? The quality of preservation, is almost unmatched and quarry operationshave been carried out carefully with an awareness of the value of the fossils. But thesefactors do not account for the interesting question of how there came to be such aconcentration of pregnant ichthyosaurs in a particular place very close to their time of giving birth.
23.The passage supports which of the following conclusions?
(A) Some species of ichthyoeaurs decayed more rapidly than other species.
(B) Ichthyosaur newborns are smaller than other new born inarine reptiles.
(C) Ichthyosaurs were more advanced than terrestrial creatures.
(D) Ichthyosaurs may have gathered at Holzmaden lo give birth.
24. The word "they" in line 3 refers to
(A) skelectons
(3) scavengers
(C) creatures
(D) environments
25. All of the following are mentioned as factors that encourage fossilization EXCEPT the
(A) speed of buring
(B) conditions of the water
(C) rate at which soft tissues decay
(D) cause of death of the animal
26. Which of the following is true of the fossil deposits discussed in the passage ?
(A) They include examples of newly discovered species.
(B) They contain large numbers of well-preserved specimens.
(C) They are older than fossils found in other places.
( D ) They have been analyzed more carefully than other fossils.
27. The word "outstanding" in line 15 is closest in meaning to
(A) extensive
(B) surprising
(C) vertical
(D) excellent
28. The word "site" in line 19 is closest in meaning to
(A) example
(B) location
(C) development
(D) characteristic
29. Why does the author mention the speciment preserved in the birth canal (line 21-22)?
(A) To illustrate that the embryo fossils are quite advanced in their development
(B) To explain why the fossils are well preserved
(C) To indicate how the ichthyosaurs died
(D) To prove that ichthyosaurs are marine animals
30. The word "they" in line 25 refers to
(A) pregnant females and young
(B) quarry operations
(C) the value of the. fossils
(D) these factors
31. The phrase "account for" in line 27 is closest in meaning to
(A) record
(B) describe
(C) equal
(D) explain
32. Which of the following best expresses the relationship between the first and second paragraphs?
(A) The first paragraph describes a place which the second paragraph describes a field of study.
(B) The first paragraph defines the terms that are used in the second paragraph
(C) The second paragraph describes a specific instance of the general topic discussed in the first paragraph
(D) The second paragraph presents information that contrasts with the information given in the first paragraph
33. Where in the passage does the author mention the variety of fossils found at holzmaden?
(A) Line 1
(B) Lines 3-5
(C) Lines 13-15
(D) Lines 21-23
Questions 34-41
The Lewis and Clark expedition, sponsored by President Jefferson, was the most important official examination of the high plains and the Northwest before the War of 1812. The President s secretary. Captain Meriwether Lewis, had been instructed to "explore the Missouri River, and such principal streams of it as,by its course and communication with the waters of the Pacific Ocean. . . may offer the most direct and practicable water communication across the continent, for the purposes of commerce."
Captain William Clark, the younger brother of famed George Rogers Clark, was invited to share the command of the exploring party.
Amid rumors that there were prehistoric mammoths wandering around the unknownregion and that somewhere in its wilds was a mountain of rock salt 80 by 45 miles in extent, the two captains set out. The date was May 14,1801. Their point of departure was the mouth of the Wood River, just across the Mississippi from the entrance of the Missouri River. Aftertoiling up the Missouri all summer , the group wintered near the Mandan villages in the center of what is now North Dakota. Resuming their journey in the spring of 1805. the men worked their way along the Missouri to its source and then crossed the mountains of western Montana and Idabo. Picking up a tributary of the Columbia River , they continued westward until they reached the Pacific Ocean, where they stayed until the following spring.
Lewis and Clark brought back much new information, including the knowledge that the continent was wider than originally supposed. More specifically, they learned a good deal about river drainages and mountain barriers. They ended speculation that an easy coast-to-coast route existed via the Missouri-Columbia River systems, and their reports of the climate, the animals and birds, the trees and plants, and the Indians of the West -- though not immediately published -- were made available to scientists.
34.With what topic is the passage primarily concerned?
(A)The river systems of portions of North America
(B)Certain geological features of the North America
(C)An exploratory trip sponsored by the United States government
(D)The discovery of natural resources in the United States
35.According to the passage, the primary purpose of finding a water route across the continent was to
(A)gain easy access to the gold and other riches of the Northwest
(B)become acquainted with the inhabitants of the West
(C)investigate the possibility of improved farmland in the West
(D)facilitate the movement of commerce across the continent
36. The river Meriwether Lewis was instructed to explore was the
(A) Wood
(B) Missouri
(C) Columbia
(D) Mississippi
37. According to the passage ,the explorers spent their first winter in what would become
(A) North Dakota
(B) Missouri
(C) Montana
(D) Idaho
38. The author states that Lewis and Clark studied all of the following characteristics of the explored territories EXCEPT
(A) mineral deposits
(B) the weather
(C) animal life
(D) native vegetation
39. The phrase "Picking up" in line 20 could best be replaced by which of the following?
(A) Searching for
(B) Following
(C) Learning about
(D) Lifting
40. It can be Inferred from the passage that prior to the Lewis and Clark expedition the size of the continent had been
(A) of little interest
(B) understimated
(C) known to native inhabitants of the West
(D) unpublished but known to most scientists
41. Where in the passage does the author refer to the explorersfailure to find an easy passageway to the western part of the continent?
(A) Lines 1-3
(B) Lines 7-9
(C) Lines 18-20
(D) Lines 23-25
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